Generally, printers embed toner on paper by relying on electrical charges occurring within the printer cartridges. Printer cartridges typically include a toner hopper, a primary charge roller, and a drum. The toner is typically stored in the toner hopper and carries a negative charge. The drum is typically given a charge by a primary charge roller or PCR. The charge of the drum is typically more positive than the charge of the toner, and thus the drum is able to attract the toner. Once the drum is given a charge by the PCR and a print pattern is set, the drum gets coated with toner. The drum that is coated with toner then rolls over a sheet of paper, which is usually given a negative charge by the PCR. The charge of the paper is less negative than the charge of the toner, and thus the paper attracts the toner. The toner is embedded on the paper according to the print pattern.
Used printer cartridges of fax machines, copiers, inkjet printers, and laser printers are often remanufactured. The drum is usually one of the components that wears out from usage and gets replaced during remanufacturing. In some printer cartridges, such as those manufactured by Hewlett Packard company having model numbers HP 1600, HP 2600, and HP 2605, the drum 2 may be attached to one end of the printer cartridge 4 by a drum flange 6 (FIG. 1). The drum flange 6 may be positioned in between the drum 2 and the cartridge end cap 8. Referring to FIG. 2, a drum portion 10 of the drum flange 6 may be inserted through the drum 2 and an end cap portion 12 of the drum flange 6 may be inserted through the cartridge end cap 8. The drum flange 6 attaches the drum 2 to the printer cartridge 4 by being connected to both the drum 2 and the cartridge end cap 8. It can be realized that the drums are attached to the cartridges in a manner that may require breaking the cartridges.
It is desirable to be able to detach the drums from printer cartridges without having to break parts of the cartridges. This helps preserve the appearance of the cartridges and minimizes remanufacturing steps. Methods and apparatus for efficiently and quickly detaching the drums from the cartridges are desired and are addressed by the present invention.